NetBSD-5.0.2/sys/dev/i2c/ds1307.c
/* $NetBSD: ds1307.c,v 1.12 2008/06/08 03:49:26 tsutsui Exp $ */
/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ds1307.c,v 1.12 2008/06/08 03:49:26 tsutsui Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <dev/clock_subr.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/ds1307reg.h>
struct dsrtc_softc {
device_t sc_dev;
i2c_tag_t sc_tag;
int sc_address;
int sc_open;
struct todr_chip_handle sc_todr;
};
static void dsrtc_attach(device_t, device_t, void *);
static int dsrtc_match(device_t, cfdata_t, void *);
CFATTACH_DECL_NEW(dsrtc, sizeof(struct dsrtc_softc),
dsrtc_match, dsrtc_attach, NULL, NULL);
extern struct cfdriver dsrtc_cd;
dev_type_open(dsrtc_open);
dev_type_close(dsrtc_close);
dev_type_read(dsrtc_read);
dev_type_write(dsrtc_write);
const struct cdevsw dsrtc_cdevsw = {
dsrtc_open, dsrtc_close, dsrtc_read, dsrtc_write, noioctl,
nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
};
static int dsrtc_clock_read(struct dsrtc_softc *, struct clock_ymdhms *);
static int dsrtc_clock_write(struct dsrtc_softc *, struct clock_ymdhms *);
static int dsrtc_gettime(struct todr_chip_handle *, struct clock_ymdhms *);
static int dsrtc_settime(struct todr_chip_handle *, struct clock_ymdhms *);
static int
dsrtc_match(device_t parent, cfdata_t cf, void *arg)
{
struct i2c_attach_args *ia = arg;
if (ia->ia_addr == DS1307_ADDR)
return (1);
return (0);
}
static void
dsrtc_attach(device_t parent, device_t self, void *arg)
{
struct dsrtc_softc *sc = device_private(self);
struct i2c_attach_args *ia = arg;
aprint_naive(": Real-time Clock/NVRAM\n");
aprint_normal(": DS1307 Real-time Clock/NVRAM\n");
sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
sc->sc_dev = self;
sc->sc_open = 0;
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = NULL;
sc->sc_todr.todr_settime = NULL;
sc->sc_todr.todr_gettime_ymdhms = dsrtc_gettime;
sc->sc_todr.todr_settime_ymdhms = dsrtc_settime;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
/*ARGSUSED*/
int
dsrtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct dsrtc_softc *sc;
if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
/* XXX: Locking */
if (sc->sc_open)
return (EBUSY);
sc->sc_open = 1;
return (0);
}
/*ARGSUSED*/
int
dsrtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct dsrtc_softc *sc;
if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
sc->sc_open = 0;
return (0);
}
/*ARGSUSED*/
int
dsrtc_read(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
u_int8_t ch, cmdbuf[1];
int a, error;
if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= DS1307_NVRAM_SIZE)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < DS1307_NVRAM_SIZE) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + DS1307_NVRAM_START;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&ch, 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"dsrtc_read: read failed at 0x%x\n", a);
return (error);
}
if ((error = uiomove(&ch, 1, uio)) != 0) {
iic_release_bus(sc->sc_tag, 0);
return (error);
}
}
iic_release_bus(sc->sc_tag, 0);
return (0);
}
/*ARGSUSED*/
int
dsrtc_write(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
u_int8_t cmdbuf[2];
int a, error;
if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= DS1307_NVRAM_SIZE)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < DS1307_NVRAM_SIZE) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + DS1307_NVRAM_START;
if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
break;
if ((error = iic_exec(sc->sc_tag,
uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"dsrtc_write: write failed at 0x%x\n", a);
break;
}
}
iic_release_bus(sc->sc_tag, 0);
return (error);
}
static int
dsrtc_gettime(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct dsrtc_softc *sc = ch->cookie;
struct clock_ymdhms check;
int retries;
memset(dt, 0, sizeof(*dt));
memset(&check, 0, sizeof(check));
/*
* Since we don't support Burst Read, we have to read the clock twice
* until we get two consecutive identical results.
*/
retries = 5;
do {
dsrtc_clock_read(sc, dt);
dsrtc_clock_read(sc, &check);
} while (memcmp(dt, &check, sizeof(check)) != 0 && --retries);
return (0);
}
static int
dsrtc_settime(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct dsrtc_softc *sc = ch->cookie;
if (dsrtc_clock_write(sc, dt) == 0)
return (-1);
return (0);
}
static int
dsrtc_clock_read(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
u_int8_t bcd[DS1307_NRTC_REGS], cmdbuf[1];
int i;
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
aprint_error_dev(sc->sc_dev,
"dsrtc_clock_read: failed to acquire I2C bus\n");
return (0);
}
/* Read each RTC register in order. */
for (i = DS1307_SECONDS; i < DS1307_NRTC_REGS; i++) {
cmdbuf[0] = i;
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&bcd[i], 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
aprint_error_dev(sc->sc_dev,
"dsrtc_clock_read: failed to read rtc "
"at 0x%x\n", i);
return (0);
}
}
/* Done with I2C */
iic_release_bus(sc->sc_tag, I2C_F_POLL);
/*
* Convert the DS1307's register values into something useable
*/
dt->dt_sec = FROMBCD(bcd[DS1307_SECONDS] & DS1307_SECONDS_MASK);
dt->dt_min = FROMBCD(bcd[DS1307_MINUTES] & DS1307_MINUTES_MASK);
if ((bcd[DS1307_HOURS] & DS1307_HOURS_24HRS) == 0) {
dt->dt_hour = FROMBCD(bcd[DS1307_HOURS] &
DS1307_HOURS_12MASK);
if (bcd[DS1307_HOURS] & DS1307_HOURS_12HRS_PM)
dt->dt_hour += 12;
} else {
dt->dt_hour = FROMBCD(bcd[DS1307_HOURS] &
DS1307_HOURS_24MASK);
}
dt->dt_day = FROMBCD(bcd[DS1307_DATE] & DS1307_DATE_MASK);
dt->dt_mon = FROMBCD(bcd[DS1307_MONTH] & DS1307_MONTH_MASK);
/* XXX: Should be an MD way to specify EPOCH used by BIOS/Firmware */
dt->dt_year = FROMBCD(bcd[DS1307_YEAR]) + POSIX_BASE_YEAR;
return (1);
}
static int
dsrtc_clock_write(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
uint8_t bcd[DS1307_NRTC_REGS], cmdbuf[2];
int i;
/*
* Convert our time representation into something the DS1307
* can understand.
*/
bcd[DS1307_SECONDS] = TOBCD(dt->dt_sec);
bcd[DS1307_MINUTES] = TOBCD(dt->dt_min);
bcd[DS1307_HOURS] = TOBCD(dt->dt_hour) | DS1307_HOURS_24HRS;
bcd[DS1307_DATE] = TOBCD(dt->dt_day);
bcd[DS1307_DAY] = TOBCD(dt->dt_wday);
bcd[DS1307_MONTH] = TOBCD(dt->dt_mon);
bcd[DS1307_YEAR] = TOBCD((dt->dt_year - POSIX_BASE_YEAR) % 100);
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
aprint_error_dev(sc->sc_dev,
"dsrtc_clock_write: failed to acquire I2C bus\n");
return (0);
}
/* Stop the clock */
cmdbuf[0] = DS1307_SECONDS;
cmdbuf[1] = DS1307_SECONDS_CH;
if (iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
aprint_error_dev(sc->sc_dev,
"dsrtc_clock_write: failed to Hold Clock\n");
return (0);
}
/*
* Write registers in reverse order. The last write (to the Seconds
* register) will undo the Clock Hold, above.
*/
for (i = DS1307_NRTC_REGS - 1; i >= 0; i--) {
cmdbuf[0] = i;
if (iic_exec(sc->sc_tag,
i ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &bcd[i], 1,
I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
aprint_error_dev(sc->sc_dev,
"dsrtc_clock_write: failed to write rtc "
" at 0x%x\n", i);
/* XXX: Clock Hold is likely still asserted! */
return (0);
}
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
return (1);
}